Interventions designed to alter risk behaviors in inner city youths are central to efforts to contain the spread of the AIDS epidemic. Previous research regarding sexual activity and substance abuse in youths has underscored the importance of articulating and utilizing a theoretical framework for constructing behavioral interventions designed to reduce risk behaviors. Protection-Motivation Theory (PMT), in extending aspects of the Health Belief Model by accounting for fear appraisal, peer approval, and self-efficacy, appears to be particularly appropriate for adolescents. Three HIV risk behaviors - sexual intercourse without use of a condom, sexual intercourse with multiple partners and substance abuse - are definable, associated with increased risk of infection and theoretically alterable practices, making them ideal target behaviors. In view of the complex interactions among individual, peers, family and community in influencing these behaviors, a community-based approach offers significant theoretic advantages over other more focussed approaches. Accordingly, in the present study, we propose to assess the impact of a community-based behavioral intervention regarding AIDS risk behaviors on the use of condoms, the number of sexual partners and the use of drugs or alcohol of 100 groups of youths aged 14 to 16 years. The intervention will be based on the PMT characterized by relevant cultural, cognitive, and psychologic variables identified during the formative phase. The delivery of the intervention will be formulated in accordance with pragmatic communications models during an intensive community-based process phase. Following an introductory mass media universal intervention, a selective intervention will be implemented in 3 phases: 1) train 50 adolescents in leadership skills and culturally relevant components of PMT; 2) facilitate cohesion and skill acquisition among 50 peer groups (5-10 youths each) with the goal of promoting a positive coping appraisal in response to challenges to engage in AIDS risk behaviors; and 3) consolidate group cohesion and self-efficacy of members of these groups through goal-oriented community- based activities. The impact of the selective intervention will be assessed by comparison of reported behavioral outcomes and postulated intermediary variables between the 50 intervention peer groups and 50 non- intervention peer networks. The impact of the entire intervention effort on the whole community will be assessed by comparison of reported behaviors with intermediary variables between a community-wide pre-intervention and post-intervention population-based survey. Youths identified as "failing" will be directed to individual indicated interventions.